Pboofing cobpobation



STA S ATE '1 OFFICE.

PARKER R. BRADLEY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 AIRCRAFT FIRE- PROOFING- CORPORATION, OF NUTLEY, NEW JERSEY, A CORPORATION OF NEW Patented July 8, 1919.

JERSEY.

METHOD OF FIREPBDOFING AIRCRAFT.

1,309,453 Specification of Letters Patent.

No Drawing. Application filed December 22, 1917. Serial No. 208,447.

To all 'whom it may concern:

Be it known that I, PARKER R. BRADLEY, a citizen of the United .States, and a resident of East Orange, in the county of Essex and State of New Jersey, have invented a new and Improved Method of Fireproofing Aircraft, of which the following is a full, clear, and exact description.

This invention relates to the method of and means for fireproofing inflammable parts'of aircraft and the like, and the invention has to deal particularly with an improved protective covering for the inflammable parts, whereby gasolene or other fuel spread over the wing or frame surface by backfiring of the motors, or otherwise, may burn if ignited by BXPlOSlVGdIlCCH- diary bullets without the fire consuming the surface on which the fuel burns, so that it is possible for the aircraft to be brought back to the earth without danger to the aviator or assengers.

The method broadly consists in applying one or more coats of a fireproof liquid to the fabric parts to be protected, and after the coat or coats have dried, one or more coats of a suitable dope are applied and also one or more coats of dope are applied to the woodwork, an after drying of the dope an adhesive or stickum dope is applied to the already coated part, and finally a suitable metal foil is laid smoothly on the surface coated with the adhesive. If the foil-covered surface is exposed to the weather, a final coating of spar varnish or the like may be employed. The fireproofing solution herein roposed fireproofs the fabric but the foil reproofs the dope which is applied to the fabric or other parts of the flying machine. One or more coats of dope may be applied to the foil, and then one or more coats of waterproof varnish applied to this coating of dope on the foil.

The method is applicable to the woodwork as Well as to the linen, cloth or other fabric constituting the wing surface, except as to the woodwork the fireproofing liquid is omitted. Preferably the linen or other fabric is fireproofed before it is put on the wing frame and while it is in long lengths. Almost any form of coating or dyeing machine may be resorted to for immersing the.

linen in the fireproof liquid, and after being immersed the cloth travels slowly through a dry box until it is thoroughly number of times.

The fireproofing liquid is made as follows:

28 ounces of ammonium phosphate 3% ounces of boric acid 7 pints of water.

Sodium tungstate, sodium acetate or other chemicals having an equivalent action may be used.

\Vhen it is desired to fireproof a completed wing the sections of the wing can be fireproofed by the method herein described by resorting to dipping and drying the sections by any suitable machine designed for that purpose. This has reference to the applying of the various liquid coats but the metal foil is laid carefully on the surface.

When the fireproofed linen, wood framework of the Wings and other partsof the aircraft are thoroughly dry four or more coats, preferably of cellulose acetate or acetyl cellulose dope, are applied either by hand labor or by dipping, and when this (lope is dry an adhesive or stickum dope is applied to the surface, and while the adhesive is still sticky the foil is laid. In

laying the foil the adhesive dope is applied to only a small part of the surface to be protected at a time, and a section of foil is then laid on the sticky adhesive, and after being carefully rubbed down so as to be perfectly smooth, the paper backing on which the foil is carried is pulled off and thrown away, and then another strip or section is applied in the same manner, the joints between the sections being preferably overlapped, although when two layers of foil are employed the sections are so laid that the second layer covers the joints of the sections forming the first layer. When the foil overlies the woodwork of the frame the foil may be tacked down by very small tacks, but adhesive is preferably used wherever possi'ble. All exposed Woodwork should be coated with dope and faced with the foil in the same manner as the wood framework of the wings above described, but care should be used to see that the foil is laid of the aircraft are thus covered with foil 21 suitable coloring coat of dope or colored paint may be applied if the foil is too brightand shiny, and finally one or more coats of spar or other oil varnish are given to the fireproofed parts.

The foil preferred for this method of fireproofing is aluminum foil of a gage about .0005 of an inch thick and measuring about 20,000 square inches to the pound. The pa.- per backing weighs about the same and can be easily stripped off from the foil. The foil may be backed with any other kind of paper or with cloth, and this foil is suitably prepared for use in this fireproofing process and then put up in rolls for convenient handling. The foil is the main protection of the dope from fire. Therefore, the greater the risk of fire the thicker should be the'foil, and it may be .001 of an inch thick, or even thicker.-

In preparing the foil the aluminum side is sprayed or otherwise covered with a StlCkUlD'l dope or other adhesive and then passed through a heated dry box, or an air-drying system without heat. Several coats may be applied in this manner, any suitable mechanical means being employed for apply ing the adhesive. The foil thus coated is next perforated in a suitable perforating machine with perforations, say, ten holes per square inch more or less, and each hole being about the size of a. large pin hole. The only object of these perforations is to allow air to-escape between the foil and the surface to be covered while the foil is being laid. If the foil is applied slowly and with care fewer and smaller holes are required,

but for quick work larger holes and more of them are desirable.

it is applied to the wings may have applied to it two or more coats of dope and when dustry, may be employed.

dry, one coat of stickum, the coated foil is applied and the paper torn ofi', no varnish being needed. After such treatment the fabric to which the foil is attached may be cut and sewed on the wing frame or other parts of the craft in the usual manner, using the foilside against the woodwork, and then the outer surface is doped and faced with foil, according to the method above explained. This double facing of foil is used where extra fireproofing is required for protection against bombardment of explosive gas shells. When foil-facing the linenin long lengths with foil, a doubling machine, commonly used in the rubber in- The various aircraft dopes now in use are 7 afi'ected by weather as well as by light, but

by the use of foil in the manner herein de scribed air, light and weather have but little, if any, effect, and furthermore the-fireproofing quality is materially improved.

appellation, and this stickum dope is prepared as follows To two parts of dope is added one part,

ing for the cloth including a slow burning substance and a metal foil disposed over the said covering- 2. A fireproof covering for the inflammable'parts of aircraft and the like, including a metal foil coated with an adhesive.

3. A fireproof covering for the inflammable parts of aircraft and the like, including a perforated metal foil coated with an adhesive.

4. In combination with a part to be protected, of one ormore coats" of slow burn- 'ing dope thereon, and a covering of foil adhering to the said coated-part.

' 5. The combination of an inflammable part to be protected, a coating of fireproof liquid dried thereon, a coating of dope dried on the first-mentioned coat, and a layer of foil adhering to the second-mentioned coat.

6. The combination of an inflammable part to be protected, a coating of fireproof liquid dried thereon, a coating of dope dried on the first-mentioned coat, a layer of foil adherin to the second-mentioned coat, and a coat 0 waterproof varnish on the foil.

.7. The combination of an inflammable part to be protected, a coating of fireproof liquid dried thereon, a coating of dope dried mable part of an aircraft or the like which consists in applying a slow burning dope liquid thereto, drying the liquid, and covering the coated part with metal foil.

10. The method of fireproofing an inflammable part of an aircraft or the like which consists in applying a slow burning liquid thereto, drying the liquid, applying an adhesive to the coated part, applying a foil with a removable backing thereon to the adhesive-covered surface and finally removing the backin from the laid foil.

11. The met 10d of fireproofing an inflammable part of an aircraft or the like which consists in applying a slow burning liquid thereto, drying the liquid, applying thereto, drying the liquid, applying an adhesive to the coated part, applying a foil with a removable backing thereon to the adhesive covered surface, removing the backing from the laid foil, ap lyin one 01' more coats of dope on the foi and applying an outer layer of one or more coats of varnish.

.13. The herein-described method of coating an inflammable part of an aircraft or the like, which consists in coating the part with a fireproof liquid, drying the coating, applying a coating of dope, applying a coating of adhesive on the surface of dope, and applying a layer of foil on the adhesive.

14. In combination with a part to be protected, one or more coats of slow burning substance thereon, and a covering of perforated foil adhering to the said coated part. 15. In a fireproof covering, a cloth, a covering including cellulose acetate dope, and a metal foil disposed over the said cellulose acetate dope.

PAS KER R. BRADLEY. 

